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प्रश्न
State whether the following statement is true or false. Correct the false statement.
Phenolphthalein is a natural indicator.
विकल्प
True
False
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उत्तर
This statement is False.
Explanation:
Phenolphthalein is a synthetic indicator.
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संबंधित प्रश्न
Five solutions, A, B, C, D and E, when tested with universal indicator, showed pH as 4, 1, 11, 7 and 9, respectively. Which solution is
- neutral?
- strongly alkaline?
- strongly acidic?
- weakly acidic?
- weakly alkaline?
Arrange the pH in increasing order of hydrogen-ion concentration.
What colour does the following indicator turn when added to an acid (such as hydrochloric acid)?
Litmus
Acids have a ______ taste and they turn ______ litmus to ______.
Which is more basic (or more alkaline)?
A solution of pH = 8 or a solution of pH = 11.
How does an antacid work?
Name two common antacids.
Someone put some universal indicator paper into vinegar. The pH is 3. What does this tell you about the vinegar?
The colour of methyl orange indicator in a solution is yellow. The pH of this solution is likely to be ______.
Here are some results of solutions tested with universal indicator paper:
| Sulphuric acid | : | Red |
| Metal polish | : | Dark blue |
| Washing-up liquid | : | Yellow |
| Milk of magnesia | : | Light blue |
| Oven cleaner | : | Purple |
| Car battery acid | : | Pink |
Arrange the solutions in order of their increasing pH values (starting with the one with the lowest pH).
Using the knowledge of acids and bases, write a secret message with the help of baking soda and beet root. Explain how it works.
(Hint: Prepare baking soda solution in water. Use this solution to write the message on a sheet of white paper with a cotton bud. Rub a slice of fresh beetroot over the message.)
